Cortex 1 was launched as part of C’Space, an event allowing students to launch experimental rockets. Stuffed with sensors and entirely 3D printed, Cortex 1 flew well, but the parachute failed to deploy mainly due to an imperfectly bonded assembly. The hatch was recovered, but the rocket was lost. Lessons were learned, and Cortex 2 was drafted up before the end of the event.

Some of the changes included tweaking the shape and reducing weight, and the refinements also led to reducing the number of fins from four to three. The fins for Cortex 2 are also reinforced with carbon fiber inserts and are bolted on to the main body.

Here’s an interesting details: apparently keeping the original fins would result in a rocket that was “overstable”. We didn’t really realize that was a thing. The results of overstabilizing are similar to a PID loop where gain is too high, and overcorrection results in oscillations instead of a nice stable trajectory.

Cortex 2 uses a different rocket motor from its predecessor, which led to another interesting design issue. The new motor is similar to hobby solid rocket motors where a small explosive charge at the top of the motor blows some time after the fuel is gone. This charge is meant to eject a parachute, but the Cortex 2 is not designed to use this method, and so the gasses must be vented. [Foaly] was understandably not enthusiastic about venting hot gasses through the mostly-PLA rocket body. Instead, a cylindrical cartridge was designed that both encases the motor and redirects any gasses from the explosive charge out the rear of the rocket. That cartridge was SLA printed out of what looks to us like Formlabs’ High Tempurature Resin.

Finally, to address the reasons Cortex 1 crashed, the hatch and parachute were redesigned for better reliability. A servo takes care of activating the system, and a couple of reverse-polarity magnets assist in ensuring the hatch blows clear. There’s even a small servo that takes care of retracting the launch guide.

“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win, and the others, too”

When President Kennedy gave his famous speech in September 1962, the art of creating liquid-fueled rocket engines of any significant size was still in its relative infancy. All the rocketry and power plants of the Saturn series of rockets that would power the astronauts to the Moon were breaking entirely new ground, and such an ambitious target required significant plans to be laid. What is easy to forget from a platform of five decades of elapsed time is the scale of the task set for the NASA engineers of the early 1960s.

The video below the break is from 1962, concurrent with Kennedy’s speech, and it sets out the proposed development of the succession of rocket motors that would power the various parts of the Saturn family. We arrive at the famous F-1 engine that would carry the mighty Saturn 5 and start its passengers on their trip to the Moon at a very early stage in its development, after an introduction to liquid rocket engines from the most basic of first principles. We see rockets undergoing testing on the stand at NASA’s Huntsville, Alabama facility, along with rather superlative descriptions of their power and capabilities.

The whole production is very much in the spirit of the times, though unexpectedly it makes no mention whatsoever of the Space Race with the Soviet Union, whose own rocket program had put the first satellite and the first man into space, and which was also secretly aiming for the moon. It’s somewhat jarring to understand that the people in this video had little idea that such an ambitious program would be as successful as it became, or even that in the wake of Kennedy’s assassination the following year there would be such an effort to fulfill the aim set out in his speech to reach the moon within the decade.

The moon landings, and the events and technology that made them possible, are a subject of considerable fascination for our community. We must have covered innumerable stories about artifacts from the Apollo era in these pages, and no doubt more will continue to come our way in the future. Films like this one do not tell us quite the same story as does a real artifact, but their values lies in capturing the optimism of the time. Anything seemed possible in 1962, and those who lived through the decade were lucky enough to see this proven.

Fifty years from now, what burgeoning engineering efforts will we look back on?

Many of us made soda bottle rockets for science class. Some of us didn’t have that opportunity, and made them in the backyard because that’s what cool kids do. Water rockets work on the premise that if water is evacuated from one side of a container, the container will accelerate away from the evacuation point. Usually, this takes the form of a 2-liter bottle, a tire pump and some cardboard fins. [François Gissy] modified the design but not the principle for his water trike which reached 261 kph or 162mph.

Parts for the trike won’t be found in the average kitchen but many of them could be found in a motorcycle shop, except for the carbon fiber wrapped water tank. There wasn’t a throttle on this rocket, the clutch lever was modified to simply open the valve and let the rider hold on until the water ran out. The front brake seemed to be intact, thank goodness.

Powering vehicles in unconventional ways is always a treat to watch and [François Gissy]’s camera-studded trike is no exception. If you like your water rockets pointed skyward, check out this launch pad for STEM students and their water rockets. Of course, [Colin Furze] gets a shout-out for his jet-powered go-kart.

Rocket engines are undeniably cool. Experiencing the roar, seeing the fire, and watching the rocket blast off into the sky… what else can you ask for? Well, for [NightHawkInLight], a transparent rocket body is the answer.

Based on previous work by [Applied Science], he uses an acrylic rod as the rocket body and as the fuel. Bring a flame into the acrylic, apply oxygen from a canister at the other end of the body and voilà! The rocket engine starts nicely, and even better, the intensity of the burn can be controlled via the amount of oxygen provided.Continue reading “Transparent Rocket Engine”→

Testing rocket motors is a dangerous business, as they have an annoying habit of releasing all of that energy a little quicker than you might like. [Jeff Hopkins] knows this, so he made his own wireless rocket motor analyzer that allows him to trigger, test and monitor rocket motors from a safe distance. This involves more than just pushing a button and watching them go whoosh: his platform measures the thrust of the prototype over 90 times a second and transmits this data to him remotely for logging and later analysis. His current prototype can measure engines with up to 400 lbs of thrust. That is a lot, so it is a good thing that his rig can also remotely arm, fire or safe the motors, all over a 70cm wireless radio link that keeps him safely out of the way. It is also built of cheap parts, so if a RUD (Rapid Unplanned Disassembly) does occur, it won’t cost him much to rebuild and start again.

This project is part of a bigger plan: [Jeff] is looking to build a high-power launch platform that can launch an electronics platform high above the earth. Could this be the beginning of the race to be the first hacker in space? We shall see…

A liquid-fuel rocket engine is just about the hardest thing anyone could ever build. There are considerations for thermodynamics, machining, electronics, material science, and software just to have something that won’t blow up on the test rig. The data to build a liquid engine isn’t easy to find, either: a lot of helpful info is classified or locked up in one of [Elon]’s file cabinets.

This engine, powered by gaseous oxygen and ethanol, is designed for 3D printing. It’s actually a great use of the technology; SpaceX and NASA have produced 3D printed engine parts using DMLS printers, but [Graham] is using the much cheaper (and available at Shapeways) metal SLS printers to produce his engine. Rocket engines are extremely hard to manufacture with traditional methods, making 3D printing the perfect process for building a rocket engine.

So far, [Graham] has printed the engine, injector, and igniter, all for the purpose of shoving oxygen and ethanol into the combustion chamber, lighting it, and marveling at the Mach cones. You can see a video of that below, but there’s also a few incredible resources on GitHub, the Fubar Labs wiki, and a bunch of pictures and test results here.

Robert’s Rocket Project has been going on for a long time. It has been around so long that you can go all the way back to posts from 2001, where he talks about getting his first digital camera! The site is dedicated to his pursuit of liquid fueled rocket engine building. It’s a great project log and he has finally come to the point where he will be testing his first flight vehicle soon.

His latest project is a 250lbf regeneratively cooled engine. It uses kerosene as the fuel, and liquid oxygen as the oxidizer. The neat thing is he utilizes the temperature change of the liquid oxygen expanding to cool the chamber and nozzle before being burned. This allows for a very efficient and powerful combustion of the fuel. He has some videos of testing it on his site, we just wonder why he doesn’t host them on YouTube or something…